Changes in gut microbial flora after Roux-en-Y gastric bypass and sleeve gastrectomy and their effects on post-operative weight loss

Bariatric surgery affects gut microbial flora due to the anatomical and physiological changes it causes in the gastrointestinal tract. Understanding the interaction between the gut flora, the type of bariatric surgery and weight loss may help improve bariatric surgery outcomes. This study was designed to compare the effects of Roux-en-Y Gastric Bypass (RYGB) and Sleeve Gastrectomy (SG) on two main phyla of the gut microbiota in humans and evaluate their potential effect on weight changes. Thirty morbidly obese patients were divided into two groups and underwent laparoscopic SG or laparoscopic RYGB. The patients' weight changes and fecal samples were evaluated at baseline and 6 months after the surgery. A microbial flora count was carried out of the phylaBacteroidetesandFirmicutesandBacteroides Fragilis. Changes in the abundance of the flora and their correlation with weight loss were analyzed. After 6 months, the patients with a history of RYGB showed a significant decrease in stoolBacteroideteswhile the reduction in the SG group was insignificant.Firmicutesabundance was almost unchanged following SG and RYGB. There was no significant change inBacteroides Fragilisabundance in either of the two groups, but a positive correlation was observed betweenBacteroides Fragilisand weight loss after SG and RYGB. Bariatric surgery can affect gut microbiota. It can be concluded that these changes are dependent on many factors and may play a role in weight loss.

Automated summary

The study compared the effects of Roux-en-Y Gastric Bypass and Sleeve Gastrectomy on gut microbiota in humans, finding that patients with a history of RYGB showed a significant decrease in Bacteroidetes while reduction in the SG group was insignificant. Changes in gut microbiota may play a role in weight loss after bariatric surgery.